Caregiver Burden and Widower Effect: Elderly's Risk of Death Substantially
Increased When a Spouse is Hospitalized or DiesStudy shows risk is greatest within 30-day window of spouse's illness and
risk worsens with certain diagnoses

BOSTON-February 16, 2006-In the largest study ever to quantify caregiver burden and the
widower effect, researchers found that for people aged 65 and older,
hospitalization of a spouse can harm the wellbeing of his or her partner and
significantly contribute to that partner's death. This risk also varies with
the ill spouse's diagnosis. The study appears in the Feb. 16 New England
Journal of Medicine.

"Our study shows that people are connected in such a
fashion that the health of one person is related to the health of another,"
reports Nicholas Christakis, MD, PhD, professor in the Department of Health
Care Policy at Harvard Medical School.

With co-author Paul Allison, PhD, professor and chair of the University of
Pennsylvania Department of Sociology, Christakis examined the effect of
illness in one spouse on the risk of illness in a partner--commonly called
the "caregiver burden." Concurrently, they looked at the effect of the death
of one spouse on the mortality of the other, known as the "widower effect."
By considering these effects together for the first time, the authors were
able to assess the implications of specific illnesses or diseases for a
partner's risk of death.

The findings, says Christakis, are striking.

"When a spouse is hospitalized,
the partner's risk of death increases significantly and remains elevated for
up to two years," he notes. The period of greatest risk is over the short
run, within 30 days of a spouse's hospitalization or death. Over this time
frame, hospitalization in a spouse can confer to a partner almost as much
risk of dying as the actual death of a spouse.

"Spousal illness or death may impose stress on a partner or deprive a
partner of social, emotional, economic, or other practical support," says
Christakis. "When a spouse falls ill or dies, partners may increase harmful
behavior, such as drinking. Stress and lack of social support may also
adversely affect immunologic measures, so spousal hospitalization may have
physiological effects on partners."

"This highly innovative study--in an enormous sample of older
people--demonstrates yet another important connection between social networks
and health," says Richard M. Suzman, PhD, associate director of the National
Institute of Aging for Behavior and Social Research. "We don't yet know the
full extent to which social networks affect health. We need to explore the
mechanisms behind the stresses associated with these hospitalizations as we
look for ways to protect people when their central relationships are
disrupted."

The study found that certain illnesses in a spouse are more harmful to
partners than others. The more a disease interferes with a spouse's physical
or mental ability, and the more burdensome it is, the worse for the health
of the partner.

The study also found that specific illnesses impacted the spouse
differently. For instance, among men with hospitalized wives, if the wife
was hospitalized for colon cancer, there was almost no effect on her
husband's mortality. But if a wife was hospitalized with heart disease, her
husband's risk of death was 12 percent higher than it would be if the wife
was not sick at all. If a wife was hospitalized with dementia, her husband's
risk was 22 percent higher. Similar effects were seen in women whose
husbands were hospitalized.

Further analyses also confirmed that the death of a spouse within the past
30 days was harmful. The death of a wife in the previous 30 days increased
her husband's risk of death 53 percent, and the death of a husband increased
his wife's risk of death by 61 percent.

Beginning in 1993 and continuing for nine years, the authors studied 518,240
couples--more than 1 million people--between the ages of 65 and 98 who were
enrolled in Medicare. Over the nine years, 383,480 husbands (74 percent) and
347,269 wives (67 percent) were hospitalized at least once, and 252,557
husbands (49 percent) and 156,004 wives (30 percent) died. The mean age of
men in the study was 75 years and the mean age of women was 72 years. This
is the largest study of its kind.

Additionally, the authors considered how age, race, and the level of poverty
modified the mortality risk of a having a sick spouse. For women, the effect
of a husband's hospitalization increased with age and the level of poverty.
For men, the effect of a wife's hospitalization increased only with age.

Although illness and death both create stress and have a negative effect on
social support for a partner, these results operate over various time
frames. This study found that the stress effect may last for a few weeks or
months, and the support effect may last for several years. Eventually, the
healthy partner adapts to the stress effect, so that the health risks of
being a caregiver decline. However, the lack of social support that is
associated with the illness or death of a partner becomes a problem, and
health risks in the partner increase again.

"Our work suggests that interventions might decrease the mortality of
caregivers," says Christakis. "Interventions are likely to be useful in
certain diseases, such as stroke and dementia, and the timing of such
interventions might be matched to the riskiest times for caregivers, for
example, just after the hospitalization of the spouse.

"It seems clear that a person's illness or death can have health
consequences for others in his or her social network," Christakis says.
"This means that efforts to reduce disease, disability, and death can be
self-reinforcing, since a decrease in the burden of these events in one
person can have a cascading benefit for others. The training and assistance
of caregivers can lower costs and also improve the health of patients and
caregivers alike."

This work was supported by the National Institute on Aging, a division of
the National Institutes of Health.